How to read the result
DSCR is a multiplier on debt service. A DSCR of 1.30x means the property or business produces 30% more cash than the annual mortgage payment. Lenders treat this surplus as the buffer that absorbs vacancy, rent voids, refurbishment or trading dips.
- 1.40x and above · clean cover. Most owner-occupier deals at this level go through underwriting without friction.
- 1.25 to 1.39x · on threshold. Likely to clear, but lenders will sense-check vacancies, lease expiries and trading volatility.
- 1.10 to 1.24x · tight. Expect lower LTV, longer amortisation profile, personal guarantee, or repricing to a more expensive product.
- Below 1.10x · declines on most lender panels. Either re-cut the deal size, or find a lender that will price the risk explicitly.
The formula
DSCR = Net Operating Income ÷ Annual Debt Service
Net Operating Income is the cash the property or business generates after operating costs and before any financing cost. On owner-occupier trading freeholds NOI is usually adjusted EBITDA (with one-off items stripped out). On investment property it is net rental income (gross rent less voids, management, repairs, ground rent and service charge shortfalls).
Annual Debt Service is the total annual outlay on the loan. On a capital + interest mortgage, this is the monthly payment multiplied by 12. On interest-only, it is loan amount multiplied by the annual interest rate.
Worked example
DSCR is £145,000 ÷ £61,740 = 2.35x. Comfortably above the 1.40x lender threshold for an owner-occupier trading freehold. Underwriting will focus on covenant and lease rather than cover ratio.
Where DSCR comes from
DSCR is the lender's single most-used cash-flow test in commercial property lending. It was popularised in US commercial real-estate finance and crossed into UK practice via the challenger banks and US-funded private credit lenders. UK clearers now use it routinely on owner-occupier and SME commercial mortgages, alongside ICR on investment deals.
Reminder. For illustrative purposes only. These calculators are educational. They are not advice. Actual lender pricing and underwriting decisions depend on covenant, LTV, sector, property condition and dozens of factors a calculator does not see. Always validate with a regulated advisor before committing to finance.
Frequently asked
What DSCR do UK commercial mortgage lenders want?
On owner-occupier trading freeholds, lenders want 1.25x to 1.40x. On goodwill-heavy trading businesses (hospitality, care homes) lenders want 1.40x to 1.60x. On corporate-grade single-tenant assets, lenders sometimes accept 1.15x to 1.25x if the covenant is exceptional.
How do you calculate DSCR for a commercial mortgage?
DSCR equals Net Operating Income divided by Annual Debt Service. NOI is rental or trading cash flow after operating costs but before financing. Annual Debt Service is total annual loan payments (capital plus interest if amortising, interest only if interest-only).
What is a good DSCR?
Anything at or above lender thresholds is workable. 1.40x is a robust DSCR for most owner-occupier UK commercial mortgages. Below 1.20x deals get tight and usually need either lower LTV, a longer amortisation profile, or stronger covenant to bridge the gap.
What is the difference between DSCR and ICR?
DSCR uses total debt service (capital plus interest) and applies to owner-occupier and trading-business deals. ICR (Interest Cover Ratio) uses interest only and applies to investment property where lenders compare stressed rent to stressed interest cost. Both measure cash-flow cover; they just use different numerators and denominators.
Companion calculators
- ICR Calculator · the investment-property equivalent of DSCR.
- Debt Yield Calculator · the sanity-check ratio lenders run alongside DSCR.
- Stress Test Calculator · see how DSCR degrades at +1%, +2%, +3%.